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stringstream, string, and char* conversion confusion
...the temporary string const, because any changes to it might cause it to re-allocate and thus render cstr invalid. It is therefor safer to not to store the result of the call to str() at all and use cstr only until the end of the full expression:
use_c_str( stringstream.str().c_str() );
Of course,...
correct way to define class variables in Python [duplicate]
... being init always executed after the object is created, it becomes practically equal to define variables outside of init, right?
– jeanc
Jan 29 '12 at 21:33
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Make elasticsearch only return certain fields?
...fields from there. May impact performance if returned data is relatively small to the size of a whole document.
– Zaar Hai
Aug 18 '13 at 10:19
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How do I detect whether a Python variable is a function?
...
If this is for Python 2.x or for Python 3.2+, you can also use callable(). It used to be deprecated, but is now undeprecated, so you can use it again. You can read the discussion here: http://bugs.python.org/issue10518. You can do this with:
callable(obj)
If this is for Python 3.x but ...
How do you get the logical xor of two variables in Python?
...e not comparing apples to oranges, is "if xor( isApple(x), isApple(y) )" really clearer than "if isApple(x) != isApple(y)" ? Not to me!
– AmigoNico
May 21 '12 at 18:27
109
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Is there a MySQL option/feature to track history of changes to records?
...ant to audit the changes to the data - who did what and when?", you can usually use audit tables (as per the trigger example Keethanjan posted). I'm not a huge fan of triggers, but it has the great benefit of being relatively painless to implement - your existing code doesn't need to know about the ...
What does “program to interfaces, not implementations” mean?
...t worried about implementation and the interface signature determines what all operations can be done. This can be used to change the behavior of a program at run-time. It also helps you to write far better programs from the maintenance point of view.
Here's a basic example for you.
public enum La...
Get specific ArrayList item
..., or perhaps just because it's (by far) the worst of (now) 6 answers which all say essentially the same thing.
– Bernhard Barker
Aug 13 '15 at 17:37
add a comment
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How do I keep a label centered in WinForms?
...er. For example Left, Top, Right or Bottom. Fill tells the control to take all the available space in the container.
– decyclone
Dec 3 '10 at 10:42
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Why doesn't Python have a sign function?
... it wasn't accepted, because they didn't agree on what it should return in all the edge cases (+/-0, +/-nan, etc)
So they decided to implement only copysign, which (although more verbose) can be used to delegate to the end user the desired behavior for edge cases - which sometimes might require the...